Zuse's ideas, not fully implemented in the Z1, succeeded more with each Z prototype. In 1939, Zuse completed the Z2, the first fully functioning electro-mechanical computer. This was the world's first electronic, fully programmable computer. Zuse used old movie film to store his programs and data for the Z3, instead of using paper tape or punched cards. Paper was in short supply in Germany during the war.
Arrays are best when accessed in an unpredictable order.
This is in contrast to lists, which are best when accessed sequentially. Zuse was unable to convince the Nazi government to support his work for a computer based on electronic valves. The Germans thought they were close to winning the War and would not support further research. The Z4 was finished in 1949 and escaped destruction. The Z1 through Z3 models were destroyed during the war.